Pension And Postretirement Benefits (Schedule of Change in Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	$ 2,345	$ 2,257
Defined Benefit Plan, Service Cost	19	21	$ 24
Defined Benefit Plan, Interest Cost	65	82	74
Defined Benefit Plan, Benefit Obligation, Actuarial Loss (Gain)	237	168
Defined Benefit Plan, Benefits Paid	(148)	(154)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	(41)	(20)
Defined Benefit Plan, Medicare Subsidies	0	0
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	(3)	(1)
Defined Benefit Plan, Benefit Obligation, Divestiture	(105)	0
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation (Gain) Loss	(3)	(8)
Defined Benefit Plan, Benefit Obligation	2,366	2,345	2,257
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	235	235
Defined Benefit Plan, Service Cost	1	1	1
Defined Benefit Plan, Interest Cost	6	8	7
Defined Benefit Plan, Benefit Obligation, Actuarial Loss (Gain)	23	14
Defined Benefit Plan, Benefits Paid	(21)	(24)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	0	0
Defined Benefit Plan, Medicare Subsidies	0	1
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	0	0
Defined Benefit Plan, Benefit Obligation, Divestiture	0	0
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation (Gain) Loss	0	0
Defined Benefit Plan, Benefit Obligation	$ 244	$ 235	$ 235